Machine Polishing AFTER Hand ConditioningIn the first installment of this article we looked at how to safely and carefully restore oxidized, neglected single stage metallic paint by hand without using abrasives. Besides removing topical oxidation we conditioned the paint, making it more workable than it was when we started. And to some level this can prepare the paint for more advanced techniques like machine polishing to try to take the paint to an even higher level of finish quality.

In this segment, we'll take a look at how to build on the results achieved by hand by carefully machine cleaning and polishing the paint using a rotary buffer and a dual action polisher.

It's vitally important that you work on antique paint by machine with the utmost caution as using too aggressive of a product or a pad or even buffing in one area for too long can remove too much paint off the surface and the effect this will have is to change the appearance of the metallic flakes in the paint. If you remove too much paint and change the appearance of a single stage metallic finish there is no way to undo the damage except to repaint the car.

This is where you as the owner of an antique, collectible car might decide that accepting the results created by working only by hand might be the best option and stop after you've restored the finish using the non-abrasive technique by hand shared previously.

If you choose to try to machine polish an antique single stage metallic finish, then I recommend you follow the practice of,

"Use the least aggressive products to get the job done"

and above all...

Focus on the task at hand...

Tiger StripesA common visual defect created by machine polishing with too aggressive of pads and/or products or buffing too long on a panel is to create lighter and darker sections which are easily seen when viewed from a few feet away from the car. If a person is using a rotary buffer and running the buffer in a side to side, or front to back pattern, the effect will look like stripes in the paint. I've heard the term "Tiger Stripes" associated with this visual effect but cannot say for sure if this is an accurate term for the mistake.

The point being is that because the metal flake is in the paint you're directly buffing on top of, the potential exists to dramatically alter the appearance just by making one pass too many with your electric buffer. So when buffing on top of single stage metallic paints be very careful to avoid a Tiger Stripe effect. (I'm going to be using a very light touch for the rotary buffer step)

A dual action polisher like the Porter Cable 7424XP is safer than using a rotary buffer but from experience, the rotary buffer is much better at restoring and creating a smoother, higher gloss surface when used first versus just using a dual action polisher. If maximum shine is not a necessary result, then stick with only using a dual action polisher and this can include dual action polishers like the Porter Cable unit mentioned above, the Griot's Garage ROP, the Meguiar's G110v2, the Cyclo Polisher, and the Flex 3401 forced rotation, dual action polisher.

These are all dual action polishers just with differences in their designs.

Pad selectionThere are a lot of different types of foam buffing pads on the market. It would take another article just as long as this one to share all the different styles of pads available so I'll save that information for a dedicated article on this topic. For now I'm just going to share the pads I chose to use for this project and why.

Kompressor PadsThe first machine step I'm going to use on the 1973 Lincoln Continental is the 6" Purple Heavy Cutting Pad. This is a very aggressive cutting pad in and of itself but used carefully it can be used safely and successfully on vintage paints.

The reason I chose this pad is because the loops of foam fibers offer good cleaning and scrubbing action and the face of the pad is slotted or tabbed and this gives the pad the ability to flex and contort to the shape of the panel being buffed.

Another benefit to the slotted tabs is when you clean this pad on a Pad Washer the tabs separate and release any built-up polish residue and paint residue.

M80 Speed GlazeM80 is like #7 on Steroids. #7 is non-abrasive. M80 Speed Glaze on the other hand contains diminishing abrasives and on a scale from 1 t 10 ranks a 4 as it relates to how aggressive it is. Compared to a true rubbing compound it's not very aggressive. The benefit to using this product on old single stage paints is that while the diminishing abrasives are cutting the paint, because it uses the same type of feeder-oils found in the #7 formula, you are at the same time gorging the paint with feeder-oils which acts to revive the full richness of color as well as hyper-lubricating the surface as you buff.

Flex 3403 Lightweight Rotary BufferThe rotary buffer I'm using for this first machine polishing step is the Flex 3403 Lightweight Rotary Buffer. This rotary buffer weighs 5 pounds! The light weight and compact size makes it very easy to use and if you're new to using a rotary buffer this is a very easy rotary buffer to learn on as it's very easy to control. Most of learning how to use a rotary buffer is learning how to control it. When using the Flex 3403 Lightweight Rotary Buffer, it's a good idea to stick with smaller pads like you see me using for this project as larger pads, 7" and bigger, will cause excessive heat build-up.

Speed Setting: 1 on the variable speed dial which is 1100 RPM

Grit Guard Universal Pad WasherThe water in my Grit Guard Universal Pad Washer started out clear, but after cleaning my Purple Kompressor Pad multiple times after machine cleaning the entire car the water is now a soupy, grayish color.

Lid coming off the Pad Washer

Vortex Base and Water Pumps Removed from Pad Washer

Residue removed from pad sinks to the bottom of the bucket... if you don't wash this residue off your pad as you're buffing it accumulates on your buffing pad and can cause swirls as well as make buffing and wipe-off of polish more difficult.

Removed buffing residue in the pad washing solution - time to change the water...

Wolfgang Finishing Glaze 3.0This is a light cutting polish that will remove any swirls left by the rotary buffer, M80 Speed Glaze and the aggressive purple Kompressor Pad. Wolfgang Finishing Glaze is easy to work with and leaves a clear finish on any paint system. In this picture I'm using it with the Porter Cable 7424XP Dual Action Polisher with a 5.5" Flat Foam Buffing Pad. For this step you could substitute any light cutting polish.

Speed Setting = 5.0 to 6.0

XMT 360This is a step most people wouldn't do and you can skip but it's a step I like to do and here's why: XMT 360 is a light machine applied cleaner/wax that polishes to a high gloss. The reason I chose this product is to clean off any left over residues from all the previous steps while leaving behind a high shine that's dry to the touch, not oily. This product also will ensure any minor swirls or defects missed by the Wolfgang Finishing Glaze are removed. This cleaner/wax has a long buffing cycle which gives you lots of time to work a panel and wipes off incredibly easy. For this step you can substitute any quality light cleaner/wax.

Like the Wolfgang Finishing Glaze, I'm using a soft, white foam polishing pad. Out of all the different polishing pads available, regardless of the design, the polishing category is one of, if not the most versatile pads available and if you're into machine polishing you should have a good collection of polishing pads on hand.